1. Field of the Invention
This invention relates to an ink jet recording apparatus and method and, in particular embodiments, to such an apparatus and method with a head cleaning system for cleaning the ink jetting surface or surfaces of an ink jet head.
2. Related Art
Ink jet recording devices have become increasingly more popular as the demand for high speed, high quality printing increases. Typical ink jet devices include a print head having one or more jetpacks, each having a Jetting surface (or orifice surface). A jetting surface is typically provided with one or more orifices through which ink (or other suitable medium) is selectively expelled.
However, in both solid ink or liquid ink jet recording devices, debris and excess residual ink tends to accumulate on the jetting surface of an orifice plate. Such accumulations often lead to jet outages and, therefore, faulty printing. A jet outage can occur when a piece of debris lands across an orifice or an excessive buildup of ink interferes with the jetting action through the orifice.
Another common cause of jet outages is a failure to provide or maintain a suitable meniscus formation at the orifice. Many ink jet devices require a suitable formation of ink meniscus at each jetting surface orifices to provide proper hydraulic action and, thus, desired ink droplet formations. The break-up of this meniscus formation can cause depriming of the system. Such meniscus formation tends to be interrupted from time-to-time, during printing operations, e.g., by air bubbles, or other environmental factors.
In order to remove unwanted material on the orifice surface, some ink jet printers have been equipped with a feature where an operator can clean the surface by either vacuum purging, pressure purging and/or wiping with an absorbent medium. However, such orifice cleaning methods that use either a vacuum or pressure source tend to waste significant amounts of ink during purging processes.
Along with the purging system, some printers utilize paper or absorbent media to blot out or wipe off debris and residual ink off the orifice surface. Yet other systems use a bin or tray that collects waste ink. These systems typically require an operator to initiate the cleaning process and then discard the wasted byproducts. As a result, printing may need to be interrupted for the operator initiated cleaning process, ink and/or other consumable material may be wasted, and the costs associated with each of the above and with the discarding of the waste material are incurred. Moreover, the vacuum, pressure and blotting type actions may increase the chance of meniscus breakdowns, resulting in jet outages.
Other ink jet apparatuses have employed a cleaning blade for cleaning the jetting surface of the ink jet head. With the blade arranged in a fixed location, the ink jet head is moved past the blade so that the blade wipes the jetting surface with the head motion. However, the blade can be (or can become) misaligned with the ink jet head such that the blade surface fails to sufficiently contact the entire orifice surface or applies a varying degree of pressure across the orifice surface. Thus, an unaligned blade may not sufficiently remove excess ink or debris from the ink jet head and, in some instances, may even channel excess ink or debris to various locations on the print head, creating build-ups or pooling at such locations.
In addition, these systems typically provide for head cleaning only after an ink jet outage has occurred or provide for wiping operations relatively often which can result in excessive blade wear. Moreover, the blade tends to abrade and tatter after prolonged use, resulting in an ineffective and inefficient cleaning process.